eh, i mean the large outcry did change Biden's statement from "israel can do anything to gaza in the interest of self defense" to "israel have to leave civilians alone" and even retracted his statement about beheaded babies when people asked for hard evidence, which is quite significant for me because afaik US president never back down their support to israel's press release ever in my life.
we're living in the time where people are given tools to challenge official governments' propaganda and act swiftly massively, for better and for worse.
also organizing such protest is usually how citizens create network for possible help and donation directly to people in need and create safe space for people affected by media propaganda (i.e. preventing physical assault, defending people being doxxed for protesting, etc.)
like i said, not everybody in capable position and not everybody has the privilege to set aside some of their resources (time, mental load) to tune in foreign policies. but the ones that do is never too insignificant if it helps a single livelihood.